Air conditioning system



y 193g. 5. M. ANDERSON 2, ,2

AIR CONDITIONING SYSTEM Filed Dec. 23, 1937 5OURCE ELECTRIC RE FRIGERATE D HATER 5OURCE INVENTOR.

BY W J ATTORNEY.

AIR CONDITIONING SYSTEM Samuel M. Anderson, Sharon, Masa, asslgnor to B. F. Mass.

Sturtevant Company, Hyde Park, Boston,

Application December 23, 1937, Serial No. 181,364

2 Claims.

This invention relates to systems for the conditioning of air and relates more particularly to air washer systems for passenger vehicles.

Air conditioning systems utilizing air washers are preferable, it is believed, for passenger vehicles such, for example, as railway passenger cars. The air is cleaned and odors and harmful bacteria are removed. During a large portion of the time evaporative cooling may be employed with resulting saving in refrigeration.

A feature of this invention resides in providing an air washer system in which a wet bulb thermostat adjusts the air control dampers for 100% outdoor air when the wet bulb temperature of the outdoor air is low enough for evaporative cooling to be efiective and at the same time adjusts a by-pass around the source of refrigerated water so that during the periods in which evaporative cooling may be effective, the spray water is continuously recirculated. When the wet bulb temperature of the outdoor air rises above 64" F., the dampers are set for say, recirculated and 25% outdoor air and an indoor thermostat is placed in condition to close the by-pass around the source of refrigerated water when the indoor air is too warm and to open the bypass when the indoor air is too cool.

Another feature of the invention resides in providing one or more thermostats at the output of the air washer, as in an air discharge duct for controlling the addition of heat to the air before it is discharged into the passenger space. One such duct thermostat may set the thermo stat for the floor heating coils.

According to another feature of the invention, the sprays are operated continuously except when the temperature of the outdoor air falls to a predetermined minimum at which time the pump supplying water to the spray nozzles; is shut down.

An object of the invention is to provide an effective air washer system for passenger vehicles.

Amirther object of the invention is to provide an a washer system for passenger vehicles which maybe operated in evaporative cooling during warm and mild weather.

Another object of the invention is to provide efiicient and effective controls for an air washer system for passenger vehicles.

. Other objects of the invention will be apparent from the drawing and the description which follows.

The invention will now be desc b d with reference to the drawing which illustrates diagrammatically one embodiment of an air conditioning system for a passenger-vehicle, according to this invention.

The blowers 9 and air washer l9 are located ,5 in one end of the railway passenger car 8. The blowers 9 draw fresh air through the vestibule grille I, and recirculated air through the grille B. The dampers ll adjusted by the motor l2 control the volume of recirculated air.

The washer l9 contains the heater 29 which is adapted to be supplied with steam from the source 28, the addition of steam being controlled by the valve 21 adjusted by the solenoid 26 under control of the duct thermostat 25.

The washer L9 also contains the spray nozzles 5 supplied with water by the pump 20 which is driven by the motor 2|. The suction line of the pump 20 is connected to the three-way valve it which in one extreme position connects the pump 20 with the pipe 40 supplying water from the refrigerated water source 11, and in the other extreme position connects the pump 20 with the pipe 4| connecting with the sump l8 and forming a by-pass around the source II. Return. water from the washer l9 flows through the pipe 62 into the sump l8 and then through the pipe 43 into the pipe 4| or into the source II, depending upon the position of the valve I 6.

The floor heating coils 36 are adapted to be supplied with steam as from the steam source 35, the addition of steam being adjusted by the valve 34. adjusted by the solenoid 33 under control of the thermostat 32.

The wet bulb thermostat l0 exposed to the outdoor air entering the system controls the damper motor I2 and cuts the indoor thermostat l4 in and out of control of the solenoid l5 which adiusts the by-pass valve is.

When the wet bulb temperature oi the outdoor air is below, say 64 F., the thermostat Ill closes the dampers II by energizing the motor l2 and by energizing the 'relay I 3 to disconnect the thermostat Id from control of the solenoid I5. This causes the solenoid It to become deenergized and to adjust the valve l8 to open the by-pass around the refrigerated water source I! so as to cause the water between sump l8 and washer [9 to be recirculated in an evaporative cooling cycle. The pump 20 operates continuously so long as the outdoor dry bulb is above 55 F. Below this temperature, the thermostat 22 deenergizes the pump motor 2| to stop the pump 20.

when the wet bulb temperature of the outdoor 5g air is above 64 F., the thermostat l0 opens its contacts to deenergize the motor l2, causing the dampers II to open to provide 75% recirculated air with 25% outdoor air. The relay [3 is deenergized and its control contacts close to connect the thermostat ll in circuit with the solenoid II and the electric source 23. The thermostat I. then acts to open' and close the by-pass around the refrigerated water source I! when the temperature within the passenger space is correct and too high respectively. If the temperature within the car falls too low and the thermostat H cannot control this, the thermostat 24 acts at say 72 F. to connect theduct thermostat 25 in circuit with the electric source 3| and with the solenoid 28 controlling the valve 21 in the steam line between the overhead heater 29 and the steam source 2|. The thermostat 25 controls the heater '2! to cause the temperature 01' the air supplied to the car to be at say 75 F.

At the same time the relay 30 is energized to connect the thermostat 32 in circuit with the electric source 32 to enable it to control the solenoid J3 to control the supply of steam from the source 35" to the floor heating coils 36.

While only one duct-thermostat has been illustrated and described, other duct thermostats functioning at different temperatures may be used for controlling the heat added to the air in the car.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated and described, since many departures may be suggested by those skilled in the art, without departing from the spirit of the invention.

What is claimed is:

1. Air conditioning apparatus comprising an air washer, means for supplying outdoor and recirculated air into said washer, a source of refrigerated water, a pump for supplying water from said source to said washer, means forming a bypass around said source and connected to said pump whereby water may be recirculated through said washer without being cooled by said source, means including thermostatic means responsive to changes in outdoor wet bulb temperatures for adjusting said first mentioned means for increas-- ing the proportion of outdoor and for decreasing the proportion of recirculated air entering said washer, when the wet bulb temperature of the outdoor air is low enough for evaporative cooling to be effective, an indoor thermostat, means controlled by said thermostat for adjusting said by-pass towards open positionwhen the indoor temperature is at or below a desired standard and for adjustingsaid by-pass towards closed position when the indoor temperature is above said standard, and means controlled by said thermostatic means for rendering said thermostat ineitective to control the adjustment 0! said bypass when the wet bulb temperature of the outdoor air is low enough for evaporative cooling to be eil'ective.

2. Air conditioning apparatus comprising an air washer,' means for supplying outdoor and recirculated air into said washer, a source of refrigerated water, a pump for supplying water from said source to said washer, means. forming a by-pass around said source and connected to said pump whereby water may be recirculated through said washer without being cooled by said source, means including thermostatic means responsive to changes in outdoor wet bulb temperatures for adjusting said first mentioned means for increasing the proportion oi outdoor and for decreasing the proportion of recirculated air entering said washer, when the wet bulb temperature of the outdoor air-is low enough for evaporative cooling to be eflective, an indoor thermostat, means controlled by said thermostat for adjusting said by-pass towards open position when the indoor temperature is at or below a desired standard and for adjusting said by-pass towards closed position when the indoor temperature is above said standard, means controlled by said thermostatic means for disconnecting said thermostat when the wet bulb temperature of the outdoor air is low enough for evaporative cooling to be elective, and means including an outdoor thermostat for disconnecting said pump when the temperature of the outdoor air falls to a predetermined level.

SAMUEL M. ANDERSON, 

